A systematic review on the efficacy of tranexamic acid in head and neck surgery

BACKGROUND

Intraoperative and postoperative blood loss is a major risk in head and neck (H&N) surgery. Recently the use of tranexamic acid (TXA) has been investigated by multiple studies for reducing intraoperative and postoperative bleeding, however reported results are variable.

OBJECTIVES

To determine the safety and efficacy of TXA use in H&N surgery.

METHODS

Systematic review of MEDLINE, EMBASE, CINAHL, Cochrane Library, PubMed, ClinicalKey, and Clinicaltrials.gov according to the PRISMA guidelines. Studies were included if they reported on intraoperative bleeding, volume or duration of postoperative drain or return to theatre rate for postoperative haemorrhage in adult populations following use of TXA. Risk of bias assessment with Cochrane Risk of Bias (RoB2) tool for randomised controlled trials and Newcastle-Ottawa Scale tool for non-randomised studies.

RESULTS

Sixteen studies were identified (114 407 patients). Eight studies evaluated TXA in major H&N surgery and eight studies in tonsillectomy. Primary outcomes were reduction in intraoperative or postoperative bleeding. Secondary outcomes included the duration of postoperative drain placement and return to theatre rate. No adverse events were reported in any patients. TXA is effective in reducing intraoperative blood loss in tonsillectomy. However, the effect on posttonsillectomy haemorrhage was unclear. Insufficient evidence exists of benefit of TXA on intraoperative bleeding in major H&N procedures. Postoperative drainage volumes were significantly reduced in most major H&N studies. The duration of drain placement and risk of blood transfusion was unchanged in most cases.

CONCLUSION

TXA use is safe in H&N patients. Whilst sufficient evidence exists to support the use of TXA in tonsillectomy, insufficient evidence exists to recommend use in major H&N surgery.

A retrospective cohort study of telephone versus face-to-face clinics for the management of new otology referrals

PURPOSE

To compare outcomes of telephone and face-to-face consultations for new otology referrals and discuss the wider use of telemedicine in otology.

METHODS

Retrospective cohort study including new adult otology referrals to our unit, sampled consecutively between March 2021 and May 2021, seen in either a face-to-face or telephone clinic. Primary outcome measure was the proportion of patients with a definitive management outcome (discharged or added to waiting list for treatment) versus the proportion of patients requiring follow-up for further assessment or review.

RESULTS

150 new patients referred for a routine otology consultation (75 telephone, 75 face-to-face) were included. 53/75 patients (71%) undergoing a face-to-face consultation received a definitive outcome following initial review, versus 22/75 (29%) telephone patients (χ² < 0.001, OR 5.8). 52/75 (69%) telephone patients were followed up face-to-face for examination. The mean (SD) number of appointments required to reach a definitive outcome was 1.22 (0.58) and 1.75 (0.73) in the face-to-face and telephone cohorts, respectively (p < 0.001).

CONCLUSIONS

Telephone clinics in otology have played an important role as part of the COVID19 response. However, they are currently limited by a lack of clinical examination and audiometry. Remote assessment pathways in otology that incorporate asynchronous review of recorded examinations alongside audiometry, either conventional or boothless, may mitigate this problem; however, further research is required.

Electrical impedance guides electrode array in cochlear implantation using machine learning and robotic feeder

Cochlear Implant provides an electronic substitute for hearing to severely or profoundly deaf patients. However, postoperative hearing outcomes significantly depend on the proper placement of electrode array (EA) into scala tympani (ST) during cochlear implant surgery. Due to limited intra-operative methods to access array placement, the objective of the current study was to evaluate the relationship between EA complex impedance and different insertion trajectories in a plastic ST model. A prototype system was designed to measure bipolar complex impedance (magnitude and phase) and its resistive and reactive components of electrodes. A 3-DoF actuation system was used as an insertion feeder. 137 insertions were performed from 3 different directions at a speed of 0.08 mm/s. Complex impedance data of 8 electrode pairs were sequentially recorded in each experiment. Machine learning algorithms were employed to classify both the full and partial insertion lengths. Support Vector Machine (SVM) gave the highest 97.1% accuracy for full insertion. When a real-time prediction was tested, Shallow Neural Network (SNN) model performed better than other algorithms using partial insertion data. The highest accuracy was found at 86.1% when 4 time samples and 2 apical electrode pairs were used. Direction prediction using partial data has the potential of online control of the insertion feeder for better EA placement. Accessing the position of the electrode array during the insertion has the potential to optimize its intraoperative placement that will result in improved hearing outcomes.

A Capacitive Cochlear Implant Electrode Array Sensing System to Discriminate Fold-Over Pattern

Purpose During insertion of the cochlear implant electrode array, the tip of the array may fold back on itself and can cause serious complications to patients. This article presents a sensing system for cochlear implantation in a cochlear model. The electrode array fold-over behaviors can be detected by analyzing capacitive information from the array tip. Method Depending on the angle of the array tip against the cochlear inner wall when it enters the cochlear model, different insertion patterns of the electrode array could occur, including smooth insertion, buckling, and fold-over. The insertion force simulating the haptic feedback for surgeons and bipolar capacitance signals during the insertion progress were collected and compared. The Pearson correlation coefficient (PCC) was applied to the collected capacitive signals to discriminate the fold-over pattern. Results Forty-six electrode array insertions were conducted and the deviation of the measured insertion force varies between a range of 20% and 30%. The capacitance values from electrode pair (1, 2) were recorded for analyzing. A threshold for the PCC is set to be 0.94 that can successfully discriminate the fold over insertions from the other two types of insertions, with a success rate of 97.83%. Conclusions Capacitive measurement is an effective method for the detection of faulty insertions and the maximization of the outcome of cochlear implantation. The proposed capacitive sensing system can be used in other tissue implants in vessels, spinal cord, or heart.

Usability and Practicality of a Novel Mobile Attachment for Aural Endoscopy (endoscope-i): Formative Usability Study

Background

Our aims were to determine the usability and practicality of the endoscope-i system, a novel mobile attachment for aural endoscopy. This incorporated assessing the ease of use of the endoscope-i for different professionals, and ultimately improving the system by receiving constructive feedback.

Objective

Our objectives were to assess the ease of the endoscope-i system in conducting an aural examination and to assess its feasibility for integrating its use into clinical practice. We looked to assess its ease, effectiveness, and efficiency; to compare this to current practices with otoscopes; and to determine whether participants perceived the system to be able to produce an image of sufficient quality to make a clinical assessment. Finally, we wanted to assess the usefulness of the current training given for using the system, and we sought to gain feedback for the product from the differing specialists.

Methods

A formative usability study of the endoscope-i system was conducted with 5 health care professionals. Each session lasted 40 minutes and involved audio/video consent, a hands-on session, a private semistructured interview, and an option to discuss the device with a company representative.

Results

All participants found the endoscope-i system easy to use. The image quality was perceived to be greater than that achieved by current otoscopes. The ability to record images and view them retrospectively was also seen as a positive.

Conclusions

This study has not identified any significant issues relating to the design, functionality, or application of the endoscope-i. Participants perceived the system as superior to current options with a directly positive impact on their clinical practice.

Telescopic otology referrals: Evaluation of feasibility and acceptability

OBJECTIVE

A remote telemedical otology referral and advice service was introduced to interested general practices. General practitioners (GPs) were given a new device, "endoscope-i" that combines an optimized smartphone high definition video app with an otoendoscope. They were specifically trained to examine and capture images of patients' eardrums, which were sent electronically with a summary of clinical information and an in-app hearing testing (if required), for specialist advice to two ear, nose, and throat (ENT) consultants. We describe the findings from an evaluation of the first 6 months of this service to establish the feasibility and acceptability of an otology telemedical referral and advice service.

METHODS

The new service was advertised to GP practices in Northern Staffordshire. All interested GPs were provided with training and equipment to deliver the remote referral service. Data were collected from GPs at baseline, informal feedback in response to referral outcomes and end of service feedback. Referral data were collected routinely during the service delivery.

RESULTS

Fifteen GP leads from 15 practices received training and equipment. One quickly lost the equipment. Of the remaining 14 practices, eight sent a total of 53 remote referrals using this technology over 6 months. The most common reason for referral was an uncertainty of what could be seen in or around the eardrum. The primary barrier for implementation was lack of wireless internet connections within practices. GPs reported that they used this technology to share examination findings with patients.

CONCLUSIONS

GPs were positive about the technology, from initial engagement with training and after advice were given. Some GPs expanded the role of the technology to a consultation aid. Referral volume was manageable. Commissioners should consider tariffs structures for such services; empirical cost-effectiveness and workload-impact evaluation would inform this.

A hand-guided robotic drill for cochleostomy on human cadavers

Background

An arm supported robotic drill has been recently demonstrated for preparing cochleostomies in a pilot research clinical trial. In this paper, a hand-guided robotic drill is presented and tested on human cadaver trials.

Methods

The innovative smart tactile approach can automatically detect drilling mediums and decided when to stop drilling to prevent penetrating the endosteum. The smart sensing scheme has been implemented in a concept of a hand guided robotic drill.

Results

Experiments were carried out on two adult cadaveric human bodies for verifying the drilling process and successfully finished cochleostomy on three cochlea. The advantage over a system supported by a mechanical arm includes the flexibility in adjusting the trajectory to initiate cutting without slipping. Using the same concept as a conventional drilling device, the user will also be benefit from the lower setup time and cost, and lower training overhead.

Conclusion

The hand-guided robotic drill was recently developed for testing on human cadavers. The robotic drill successfully prepared cochleostomies in all three cases.

A Comparison of Cochlear Nerve Size in Normal-Hearing Adults Using Magnetic Resonance Imaging

OBJECTIVE

Cochlear implantation is a clinical and cost-effective treatment for severe hearing loss. Cochlear nerve size assessment by magnetic resonance imaging (MRI) has been investigated for use as a prognostic indicator following cochlear implantation. This study aimed to further that research by assessing nerve size in normal-hearing adults for symmetry.

MATERIALS AND METHODS

Patients with tinnitus presenting to our center retrospectively had their nerve size assessed by MRI.

RESULTS

The study found no significant differences between right and left cochlear nerves in normal-hearing adults, supporting our hypothesis of symmetry in these individuals. This was a previously unproven and uninvestigated hypothesis.

CONCLUSION

Nerve size assessment should remain an active area of research in otological disease.

endoscope-i: an innovation in mobile endoscopic technology transforming the delivery of patient care in otolaryngology

INTRODUCTION

Digital and mobile device technology in healthcare is a growing market. The introduction of the endoscope-i, the world's first endoscopic mobile imaging system, allows the acquisition of high definition images of the ear, nose and throat (ENT). The system combines the e-i Pro camera app with a bespoke engineered endoscope-i adaptor which fits securely onto the iPhone or iPod touch. Endoscopic examination forms a salient aspect of the ENT work-up. The endoscope-i therefore provides a mobile and compact alternative to the existing bulky endoscopic systems currently in use which often restrict the clinician to the clinic setting. Areas covered: This article gives a detailed overview of the endoscope-i system together with its applications. A review and comparison of alternative devices on the market offering smartphone adapted endoscopic viewing systems is also presented. Expert commentary: The endoscope-i fulfils unmet needs by providing a compact, highly portable, simple to use endoscopic viewing system which is cost-effective and which makes use of smartphone technology most clinicians have in their pocket. The system allows real-time feedback to the patient and has the potential to transform the way that healthcare is delivered in ENT as well as having applications further afield.

Patient safety in otolaryngology: a descriptive review

Human evaluation and judgement may include errors that can have disastrous results. Within medicine and healthcare there has been slow progress towards major changes in safety. Healthcare lags behind other specialised industries, such as aviation and nuclear power, where there have been significant improvements in overall safety, especially in reducing risk of errors. Following several high profile cases in the USA during the 1990s, a report titled "To Err Is Human: Building a Safer Health System" was published. The report extrapolated that in the USA approximately 50,000 to 100,000 patients may die each year as a result of medical errors. Traditionally otolaryngology has always been regarded as a "safe specialty". A study in the USA in 2004 inferred that there may be 2600 cases of major morbidity and 165 deaths within the specialty. MEDLINE via PubMed interface was searched for English language articles published between 2000 and 2012. Each combined two or three of the keywords noted earlier. Limitations are related to several generic topics within patient safety in otolaryngology. Other areas covered have been current relevant topics due to recent interest or new advances in technology. There has been a heightened awareness within the healthcare community of patient safety; it has become a major priority. Focus has shifted from apportioning blame to prevention of the errors and implementation of patient safety mechanisms in healthcare delivery. Type of Errors can be divided into errors due to action and errors due to knowledge or planning. In healthcare there are several factors that may influence adverse events and patient safety. Although technology may improve patient safety, it also introduces new sources of error. The ability to work with people allows for the increase in safety netting. Team working has been shown to have a beneficial effect on patient safety. Any field of work involving human decision-making will always have a risk of error. Within Otolaryngology, although patient safety has evolved along similar themes as other surgical specialties; there are several specific high-risk areas. Medical error is a common problem and its human cost is of immense importance. Steps to reduce such errors require the identification of high-risk practice within a complex healthcare system. The commitment to patient safety and quality improvement in medicine depend on personal responsibility and professional accountability.

Characterizing human vestibular sensory epithelia for experimental studies: new hair bundles on old tissue and implications for therapeutic interventions in ageing

Balance disequilibrium is a significant contributor to falls in the elderly. The most common cause of balance dysfunction is loss of sensory cells from the vestibular sensory epithelia of the inner ear. However, inaccessibility of inner ear tissue in humans severely restricts possibilities for experimental manipulation to develop therapies to ameliorate this loss. We provide a structural and functional analysis of human vestibular sensory epithelia harvested at trans-labyrinthine surgery. We demonstrate the viability of the tissue and labeling with specific markers of hair cell function and of ion homeostasis in the epithelium. Samples obtained from the oldest patients revealed a significant loss of hair cells across the tissue surface, but we found immature hair bundles present in epithelia harvested from patients >60 years of age. These results suggest that the environment of the human vestibular sensory epithelium could be responsive to stimulation of developmental pathways to enhance hair cell regeneration, as has been demonstrated successfully in the vestibular organs of adult mice.

Intraoperative Cone-Beam Computed Tomography and Multi-Slice Computed Tomography in Temporal Bone Imaging for Surgical Treatment

Objective

Conventional computed tomography (CT) imaging is the standard imaging technique for temporal bone diseases, whereas cone-beam CT (CBCT) imaging is a very fast imaging tool with a significant less radiation dose compared with conventional CT. We hypothesize that a system for intraoperative cone-beam CT provides comparable image quality to diagnostic CT for identifying temporal bone anatomical landmarks in cadaveric specimens.

Study Design

Cross-sectional study.

Setting

University tertiary care facility.

Subjects and Methods

Twenty cadaveric temporal bones were affixed into a head phantom and scanned with both a prototype cone-beam CT C-arm and multislice helical CT. Imaging performance was evaluated by 3 otologic surgeons and 1 head and neck radiologist. Participants were presented images in a randomized order and completed landmark identification questionnaires covering 21 structures.

Results

CBCT and multislice CT have comparable performance in identifying temporal structures. Three otologic surgeons indicated that CBCT provided statistically equivalent performance for 19 of 21 landmarks, with CBCT superior to CT for the chorda tympani and inferior for the crura of the stapes. Subgroup analysis showed that CBCT performed superiorly for temporal bone structures compared with CT. The radiologist rated CBCT and CT as statistically equivalent for 18 of 21 landmarks, with CT superior to CBCT for the crura of stapes, chorda tympani, and sigmoid sinus.

Conclusion

CBCT provides comparable image quality to conventional CT for temporal bone anatomical sites in cadaveric specimens. Clinical applications of low-dose CBCT imaging in surgical planning, intraoperative guidance, and postoperative assessment are promising but require further investigation.

Chlorhexidine ototoxicity in ear surgery part II: survey of preparation solution used by otolaryngologists in Canada: is there a cause for concern?

OBJECTIVE

To conduct a survey of the antiseptic preparations used for ear surgeries among otolaryngologists in Canada.

METHODS

An electronic survey was sent to active members of the Canadian Society of Otolaryngology-Head and Neck Surgery via e-mail. Questions included the use of antiseptic, choice of preparation solution, duration of preparation, use of a barrier method, and compliance with hospital protocol changes.

RESULTS

The e-mail was received by 253 otolaryngologists, and 85 completed the survey. Four of 85 respondents did not perform tympanoplasty surgery and were not included in the analysis. Of those who performed tympanoplasty (n  =  81), 78 of the 81 respondents (96%) used an antiseptic preparation solution at surgery, whereas 3 respondents (4%) did not. Sixty-six of the 77 respondents (86%) used aqueous povidone-iodine, 4 (5%) used a chlorhexidine-based preparation, 3 (4%) used an alcohol-based solution, 3 (4%) used others, and 1 answered "I don't know." Thirty-eight of 75 (29%) respondents used a barrier method, 23 (31%) answered "always," 18 (24%) answered "sometimes," and 5 (7%) answered "I don't know." When asked if they would comply with a hypothetical hospital policy to use chlorhexidine in ear surgery, 15 of 79 (19%) respondents agreed, whereas 64 (81%) disagreed. Among the aqueous povidone-iodine users (n  =  66), 7 (11%) agreed to change to chlorhexidine.

CONCLUSIONS

There is a wide variation in practice in the use of surgical preparation solution among otolaryngologists performing ear surgery. Surgeons must be vigilant to avoid ototoxicity. A national society consensus on appropriate preparation solutions for ear surgery would minimize patients' risk and minimize future medicolegal actions.

Chlorhexidine ototoxicity in ear surgery, part 1: review of the literature

OBJECTIVE

Chlorhexidine is a common antiseptic used to prevent surgical infection. However, its exposure to the middle ear may lead to deafness. The mechanisms of the ototoxicity of chlorhexidine are reviewed. The importance of recognizing its toxicity cannot be overstated in preventing injury to patients undergoing ear surgery.

METHODS

A systematic literature search was performed looking at data from human and animal studies. Search engines included MEDLINE, EMBASE, The Cochrane Library, CENTRAL, CINAHL, and Web of Science to November 1, 2010, for relevant studies published in all languages. Two independent reviewers (P.L. and D.D.P.) screened the references from published articles for additional relevant studies. Medical Subject Headings and key words including intervention (chlorhexidine, antiseptic), exposure (myringoplasty, intratympanic), and adverse effects (sensorineural hearing loss, ototoxicity, vestibular toxicity) were used.

RESULTS

Twelve studies were identified, two of which were non-English and were excluded. Only 2 articles on human subjects and 12 articles on animal models concerning chlorhexidine ototoxicity were identified.

CONCLUSIONS

Chlorhexidine in both human studies and animal models demonstrates ototoxicity if it reaches the inner ear. The toxicity of chlorhexidine appears to be related to its concentration and probable contact time with the round window membrane intraoperatively. It is conceivable that the incidence of chlorhexidine toxicity may be higher than stated if unrecognized or has resulted in subsequent medicolegal actions. From the evidence available, safer preparation solutions are available without clinical risks for ototoxicity should surgeons continue with this practice.

Transtemporal approach to otogenic brain abscesses

The standard current treatment of an otogenic brain abscess is drainage via neurosurgical burr hole or complete excision, followed by an otological procedure to eradicate the primary pathology – often at a later date. We describe the drainage of otogenic brain abscess via a transtemporal approach. We present a retrospective study of six cases, five children and one adult. All the children had acute middle ear disease while the adult patient had a petrous apex cholesteatoma. All cases had an otogenic intracranial abscess either in the posterior cranial fossa or in both posterior and middle cranial fossae. Diagnosis was confirmed by computed axial tomography (CT) scan. All the patients were treated by mastoidectomy and needle aspiration to drain the abscesses. In all cases the brain abscess and the ear pathology were successfully treated by a single stage transmastoid approach. The five paediatric patients had an extended cortical mastoidectomy approach to both intracranial pathology and ear disease except one patient who required a burr hole to drain a posteriorly located subdural posterior fossa abscess. The adult patient underwent petrosectomy, followed by transtemporal abscess drainage. There was postoperative pus recollection in one patient who required further aspiration. We conclude that transtemporal drainage of an otogenic brain abscess can successfully treat otological and intracranial pathology in a single operation. It has a low complication rate and avoids the need for a craniotomy or subsequent operations.

A surgical robot for cochleostomy

In this paper a robotic micro-drilling technique for surgery is described. The device has been deployed in cochleostomy, a precise micro-surgical procedure where the critical stage of controlling penetration of the outer bone tissue of the cochlea is achieved without penetration of the endosteal membrane at the medial surface. The significance of the work is that the device navigates by using transients of the reactive drilling forces to discriminate cutting conditions, state of tissue and the detection of the medial surface before drill break-out occurs. This is the first autonomous surgical robot to use this technique in real-time as a navigation function in the operating room and unlike other fully autonomous surgical robotic processes it is carried out without the use pre-operative data to control the motion of the tool. To control tool points in flexible tissues requires self-referencing to the tissue position in real time. There is also the need to discriminate deflections of the tissue, tissue interface, involuntary patients/tissue movement and indeed movement induced by the drill itself, which require different strategies to be selected for control. As a result of the design of the final system, the break-out process of the drill can either controlled to the required level of protrusion through the flexible interface or can be avoided altogether, with the drill bit at the medial surface. This enables, for the first time, the control of fine penetration with such great precision.

Management of nasal injuries by UK accident and emergency consultants: a questionnaire survey

OBJECTIVES

To determine how nasal injuries are managed by accident and emergency (A&E) consultants and produce a management protocol if the survey indicated a need.

METHOD

A postal survey of UK A&E consultants.

RESULTS

The response rate was 59%. A great deal of variation was found between departments and clinicians regarding the training of junior A&E staff, the equipment available, the management strategies employed, and the reasons for referral to ENT or maxillofacial departments.

CONCLUSIONS

This survey shows that many more nasal injuries could be managed within the A&E setting without referral to ENT or maxillofacial departments. A flow chart of the optimal management of nasal injuries in Accident and Emergency departments is presented.

Prenatal sonographic diagnosis of axillary cystic lymphangiomas

Cystic lymphangiomas are congenital malformations of the lymphatic system that occur most commonly in the nuchal region. Nuchal lymphangiomas are often referred to as cystic hygromas. Few cases of axillary cystic lymphangioma have been reported, but the prognosis of this lesion appears to be less grave than that of its nuchal counterpart. We present 2 cases of axillary cystic lymphangiomas that were diagnosed on prenatal sonography. In 1 case, prenatal sonography showed a multilocular, large cystic mass on the fetal left side, in the area of the lower chest and upper abdomen. The mass extended from at least the level of the umbilicus up to the neck but did not involve the neck. In the second case, prenatal sonography showed a multilocular, septate axillary cystic lymphangioma external to the chest with no flow on Doppler sonography. Follow-up sonography revealed normal fetal growth and enlargement of the cystic mass surrounding the left humerus. Both infants were delivered without complications and have been managed conservatively.

Randomized controlled trial of cervical cap with intracervical reservoir versus standard intracervical injection to inseminate cryopreserved donor semen

A prospective controlled study of donor insemination without sperm preparation or ovarian stimulation was performed to compare the use of a cervical cap incorporating an intracervical reservoir with a standard intracervical injection technique to inseminate 0.5 ml cryopreserved semen. Treatments were alternated in successive cycles in each patient after initial randomized selection. A total of 198 patients had 635 treatment cycles (median 3, range 1-7), 309 with reservoir and 326 by standard injection. A total of 56 women became pregnant, 24 (7.8% per cycle) with the reservoir and 32 (9.8% per cycle) by injection. There were no significant differences between the pregnancy rates per cycle overall or cycle-specific cumulative rates calculated using the life-table method. There were no significant differences in age, parity, baseline gonadotrophin measurements, mid-luteal serum progesterone concentrations, frequency of adverse fertility factors in the woman or her partner's cause of infertility between women who conceived and those who failed to conceive. We conclude that use of a cervical reservoir and cap for donor insemination does not offer any advantage over standard intracervical insemination.

The effect of halving the standard dose of cryopreserved semen for donor insemination: a controlled study of conception rates

Employing a common standard technique of intra-cervical insemination from straws of cryopreserved donor semen, a volume of 0.25 ml of 0.5 ml was inseminated in alternate cycles to determine if the lower volume could be used without a decrease in the conception rate. A total of 177 women were recruited and received a median of four cycles of treatment. Of these, 90 women became pregnant, 47 with 0.5 ml and 43 with 0.25 ml inseminations. The conception rates were identical for both volumes in the first nine cycles of treatment and the cumulative rates were 57.7 and 59.3%, respectively. Subsequently more pregnancies were achieved with 0.5 ml than 0.25 ml semen (nine pregnancies in 73 further cycles versus three pregnancies in 68 cycles, respectively), although the difference was not statistically significant. There were no significant differences in the women's ages, luteinizing hormone, follicle stimulating hormone, progesterone, mucus quality, mucus pH, parity or partner's diagnosis between those women who became pregnant and those who failed to conceive with either insemination dose. We conclude that the volume of semen inseminated into the cervical canal without a cervical cap can be decreased to 0.25 ml without an adverse effect on the conception rate at least in the first 9 months of treatment. This will allow more effective use to be made of valuable screened and quarantined cryopreserved semen.

Clomiphene treatment for women with unexplained infertility: placebo-controlled study of hormonal responses and conception rates

One hundred and eighteen patients with unexplained infertility were treated with clomiphene (Clomid, Merrell) in a randomized placebo-controlled cross-over study lasting up to 3 months with each preparation. Compared with placebo, clomiphene led overall to a 66% increase in mid-luteal serum progesterone levels (from mean 43 nmol/l to 71 nmol/l, p less than 0.001) and a 53% rise in the 3-month cumulative conception rate (from 14.6% to 22.33%, p less than 0.05). The greatest relative increase in conception rates with clomiphene was in women with infertility lasting more than 3 years (3-month rates from 2.9% to 14.4%, p less than 0.05). Differences in conception rates were not related to the rises in progesterone, and there was no carryover effect of clomiphene into the following placebo cycles in terms of progesterone levels or conceptions. The findings suggest that couples with unexplained infertility of less than 3 years duration are essentially normal, but with more than 3 years duration there is often a subtle disorder of ovulation that is corrected by clomiphene therapy.

The value of artificial insemination with husband's semen in infertility due to failure of postcoital sperm-mucus penetration--controlled trial of treatment

Artificial insemination with husband's semen into the cervical canal and uterine cavity (high AIH) was assessed by a randomized controlled prospective study in 46 couples whose infertility was due to failure of sperm mucus penetration, as defined by negative postcoital tests, after excluding all interfering female factors and men with sperm density less than 1 x 10(6)/ml. Seminal analysis was abnormal in 18 of the 46 men and sperm antibodies in semen were detected in 19 of the remaining 28 with normal seminal analysis. Overall, the cumulative conception rate after 6 months with AIH was 4.7 (SE 3.8)% and without treatment was 6.6 (SE 3.9)%. The results were unaffected by the findings on seminal analysis or by the presence or absence of sperm antibodies in semen. AIH appeared to be of no benefit.

Population study of causes, treatment, and outcome of infertility

Specialist infertility practice was studied in a group of 708 couples within a population of residents of a single health district in England. They represented an annual incidence of 1.2 couples for every 1000 of the population. At least one in six couples needed specialist help at some time in their lives because of an average of infertility of 21/2 years, 71% of whom were trying for their first baby. Those attending gynaecology clinics made up 10% of new and 22% of all attendances. Failure of ovulation (amenorrhoea or oligomenorrhoea) occurred in 21% of cases and was successfully treated (two year conception rates of 96% and 78%). Tubal damage (14%) had a poor outlook (19%) despite surgery. Endometriosis accounted for infertility in 6%, although seldom because of tubal damage, cervical mucus defects or dysfunction in 3%, and coital failure in up to 6%. Sperm defects or dysfunction were the commonest defined cause of infertility (24%) and led to a poor chance of pregnancy (0-27%) without donor insemination. Obstructive azoospermia or primary spermatogenic failure was uncommon (2%) and hormonal causes of male infertility rare. Infertility was unexplained in 28% and the chance of pregnancy (overall 72%) was mainly determined by duration of infertility. In vitro fertilisation could benefit 80% of cases of tubal damage and 25% of unexplained infertility--that is, 18% of all cases, representing up to 216 new cases each year per million of the total population.

Inhibition of the photosynthetic capacity of isolated chloroplasts by ozone

Isolated spinach chloroplasts have been used as a model system for studying the interaction of ozone, a component of photochemical smog, with plant membranes. Ozone bubbled into a suspension of isolated chloroplasts inhibits electron transport in both photosystems without uncoupling ATP production. Photosystem I (reduced 2,6-dichlorophenolindolphenol --> NADP(+)) is a little more sensitive than photosystem II (H(2)O --> 2,6-dichlophenolindolphenol). Ozone does not act as an energy transfer inhibitor, since the drop in ATP production and high energy intermediate (measured by amine-induced swelling) is nearly parallel to the decline in electron transport. A reasonable hypothesis is that ozone disrupts the normal pathway of energy flow from light-excited chlorophyll into the photoacts by a disruption of the components of the membrane but not a general disintegration of the membrane. In addition, ozone does not seem to penetrate into the grana region through the outer membrane of intact plastids, since ozone lowers the bicarbonate-supported O(2) evolution but does not affect the rate of ferricyanide reduction in the same plastids after osmotic disruption. This would indicate that the effect of ozone on green plants, at low concentrations, may be due to the interaction of ozone with the first membrane it contacts and not directly with internal metabolic processes.